title: Shrimp pond effluent dominates foliar nitrogen in disturbed mangroves as mapped using hyperspectral imagery.
abstract: Conversion of mangroves to shrimp ponds creates fragmentation and eutrophication. Detection of the spatial variation of foliar nitrogen is essential for understanding the effect of eutrophication on mangroves. We aim (i) to estimate nitrogen variability across mangrove landscapes of the Mahakam delta using airborne hyperspectral remote sensing (HyMap) and (ii) to investigate links between the variation of foliar nitrogen mapped and local environmental variables. In this study, multivariate prediction models achieved a higher level of accuracy than narrow-band vegetation indices, making multivariate modeling the best choice for mapping. The variation of foliar nitrogen concentration in mangroves was significantly influenced by the local environment: (1) position of mangroves (seaward/landward), (2) distance to the shrimp ponds, and (3) predominant mangrove species. The findings suggest that anthropogenic disturbances, in this case shrimp ponds, influence nitrogen variation in mangroves. Mangroves closer to the shrimp ponds had higher foliar nitrogen concentrations.
authors.affiliation: University of Twente, Faculty for Geoinformation Science and Earth Observation, P.O. Box 217, Enschede 7500 AE, The Netherlands. Electronic address: anasf69@gmail.com.
authors.forename: Anas
authors.initials: A
authors.lastname: Fauzi
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Skidmore
authors.forename: Hein
authors.initials: H
authors.lastname: van Gils
authors.forename: Martin
authors.initials: M
authors.lastname: Schlerf
authors.forename: Ignas M A
authors.initials: IM
authors.lastname: Heitkönig
mesh_terms: D000818:Animals; D017756:Aquaculture; D004784:Environmental Monitoring / Q000379:methods*; D005068:Eutrophication; D009584:Nitrogen / Q000032:analysis*; D033561:Penaeidae; D058998:Remote Sensing Technology; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical; D009584:Nitrogen
keywords: Eutrophication; Hyperspectral; Mahakam delta; Mangroves; Nitrogen concentrations; Shrimp ponds